If there were a label for this problem in the Diagnostic and Statistical Manual of Mental Disorders, it might read something like “Emotional Intimacy Deficiency—a problem characterized by a sense of shallowness in one’s relationships with others, associated with a failure to recognize or express feelings, to reveal personal details about oneself, to be vulnerable or let anyone help you, to comfortably share attention or let go of control, and to listen without having to solve a problem.”

This won’t shock you at all, but research shows men are far worse at this than women. Both sexes can certainly struggle, but this is a department where men really lag behind.

And that causes a lot of problems for men. Serious problems. Not just unfulfilling relationships — it’s more akin to a chronic emotional illness that affects every area of life.

(Men who lack emotional intimacy) take longer to recover from minor illnesses, have lower resistance levels, and have reduced survival times when diagnosed with terminal illness. They are 50 percent more likely to have a first-time heart attack, and twice as likely to die from it, than men with strong social ties. When depressed, these men have significantly lower rates of recovery than those who have close relationships… Wives who cite their husband’s “emotional unavailability” as the primary cause of divorce initiate two out of every three divorces today. At the far end of the life cycle, older men without close relationships have 20 percent lower ten-year survival rates compared with those who do.

That said, women’s friendships aren’t perfect either. We’re going to dive into the research and see the most common ways both sexes struggle with friendship, what they can do about it, and how they can learn from each other to improve.

So how do you increase emotional intimacy and build emotionally intelligent friendships? It comes down to six steps. Let’s get to it…

1) “Know thyself”

The thing everybody skips. Knowing yourself means you know what you want and need, and this is critical for both picking new friends and strengthening existing relationships.

How many friends would you optimally have? What level of closeness do you need? How frequently do you want to communicate? You want to ask yourself, “What features of a friendship will be most fulfilling to me in the long run?”

Research shows this is critical for women. We live in a world largely run by men, so women know they need close friendships to provide the things their often male-dominated-environments don’t give them.

By forming relationships with a group of women, women escape having their relationships defined by men’s way of interacting. By defining relationships for themselves, women are able to construct them in a way that is more consistent with their own beliefs.

So take some time to think about what you want and need. (No, that 2 seconds between sentences doesn’t count. Really sit down and take a half hour and think. And write stuff down.)

If you just rely on serendipity to bring you friendships and to move them forward, well, that’s what got you where you are now. Time to be a little more deliberate.

(To learn more about the science of a successful life, check out my new book here.)

So before we go to work on developing emotional intimacy, let’s find out what’s been getting in the way of it. In the modern world, what’s the biggest obstacle to adult friendships?

2) Make the time

Actually, you can’t “make time.” We all have 24 hours in a day. The more accurate thing to say is “make time with your friends a priority.” What friendships need to grow intimate and strong is hours.

Daniel Hruschka reviewed studies on the causes of conflict in friendship and found that the most common friendship fights boil down to time commitments. Spending time with someone is a sure indicator that you value him; no one likes to feel undervalued.

And the research shows this is where men make a big mistake. Whether it’s due to the longer hours men spend working or simply not making friendship the priority that women do, guys often don’t put in the time.

From the responses, it appears women were less apt to say they did not have time for friends. Although the majority (60%) of men say they have enough friends, 40% do not have enough or are unsure, a greater number than the women. It may be that some men are pulled by work and cannot find the time to balance friends, work, and family.

Unsurprisingly, in adulthood the biggest thing that takes away friend-time is family-time. And while no blogger in his right mind would ever type, “You should spend less time with your family,” he might be able to get away with saying something like the far more acceptable, “Balance is critical.”

Research has shown that in the modern era we have become far too reliant on spouses to provide all of our emotional needs — and that simply doesn’t work. So what’s a feasible solution?

Including friends in family time is not only a way to kill two birds with one stone, it also improves bothrelationships.

Most intriguing was how couples rated their own relationships more positively after interacting with other pairs. Married partners fall into routine interactions and often fail to make the effort to entertain and please as they did when they were winning each other over. Putting your best self forward for new friends allows you to shine and to see your partner through new eyes as she shines, too. Maintaining older mutual friendships also strengthens the bond between long-term partners: Having people around who think of the two of you as a unit, who admire your relationship, and who expect you to stay together can sustain you through times of doubt or distance.

So you want to make friendships a priority and give them the time they need to become emotionally intimate. And if you’re lacking hours, invite friends to join you for family time.

Okay, so you know what you want and you’re making pals a priority. But which of your friends do you need to focus on building emotional intimacy with?

3) Must, trust, rust, and just

Looking at the research, the types of friends that men and women have fall into the same four categories: must, trust, rust and just.

“Must” friends: The inner circle. The closest of the close.

“Trust” friends: Not inner circle, but people you trust, share confidences with and know are there for you.

“Rust” friends: They’re pals simply because you’ve known them a long time. (If it had more than that, they’d be “must” or “trust.”)

“Just” friends: Closer than acquaintances and you may see them regularly with a group, but you’re not tight with them and don’t have a big shared history.

What’s critical here when it comes to emotional intimacy is those “must” friends. And “trust” friends are important because they can, with work, be promoted to “must” friends.

First and foremost, you want to work on strengthening those “must” friendships and devoting more time to them. And you want to evaluate which of your “trust” friends meet with your “know thyself” criteria and might be worthy of elevation. “Rust” and “just” friends are good for rounding out your social circle but should receive less attention and investment.

(To learn more about the types of friends everyone needs, click here.)

What’s the first step in strengthening those “must” and “trust” friends — or finding totally new ones?

4) Be proactive

You’re going to need to do some legwork. You need to be proactive and initiate contact.

And you need to make concrete plans. I live in Los Angeles and in this city saying, “We should get together sometime” is pretty much synonymous with, “I have no intention of ever seeing you again.”

Specify places and times or your friendships will be determined by serendipity, which is the euphemism lazy people use for “dumb luck.”

The optimistic angle here is that if you’re being passive you can pretty much be certain other people are being passive too. So if you lead, some will follow. Organize a group, throw a party, or just invite a friend to coffee.

And what should you look for when meeting new folks who might become future “must” or “trust” friends? All the research agrees: similarity is key. Not only does it draw us to people, it also makes friendships more likely to last.

Similarities also occur when tastes and interests match up, and similarities make friendships easier to maintain. And, unless you are interested in hanging out with people who make you feel bad about yourself (not a good interest to have), finding someone who conveys that you are likeable to them will be very reinforcing to your self-esteem.

Beyond similarity, you should also look for people you want to learn something from. Since you took the time to sit down and “know thyself,” think about the person you want to be. Your best self.

Who do you want to rub off on you? To make you a better spouse, parent, worker or human being?

Okay, you know what you want, you’re making time, and you’re proactive. So what’s the real key to developing emotional intimacy with your friends?

5) Communication

Yeah, you hear “communicating is vital” constantly from experts but few ever break it down so you know how to actually do it. (These experts must not be good communicators.)

You want to focus on four primary elements: creating safety, vulnerability, emotional expressiveness, and active listening.

Creating safety: Is my friend going to feel comfortable opening up to me? Am I being too judgmental? Or, at the opposite extreme, too nosy and pushy?

Vulnerability: Are you sharing personal thoughts and feelings with them? Reciprocity is powerful and this is vital to helping both of you. Quick litmus test: are you scared to talk about the subject? Then you’re being vulnerable.

Emotional expressiveness: Don’t just talk thoughts. Talk feelings. Yours and theirs. (Guys, if you’re recoiling at this, you’re proving the point that you need to work on it.)

Active listening: Good listeners don’t just hear; they make the other person feel heard. Nod, acknowledge, and summarize what your friend said for confirmation. As former FBI hostage negotiator Chris Voss advises, if they respond “Exactly” — you’re doing it right.

Women are much better at this than men. They spend more time communicating and focus more on emotional support.

When asked the question concerning what they did with their friends, giving emotional support also was more common for women than for men.

Much of male communication is teasing the other guy (which, taken too far, is the opposite of safety.) Men feel being vulnerable is the worst thing they can do (and to be fair, the cultural ideal of the “strong, silent type” and phrases like “man up” aren’t helping any.) Males are taught not to be expressive. And guys tend to focus on problem-solving instead of listening during conversations.

We have found in our Friendship Labs that men are often willing to trade zingers and even enjoy mutual sparring, but only in limited doses. And while most will put up with it, they definitely will not open up when it’s coming at them.

That said, women face challenges here too. Because they are taught to put others at ease and say supportive things, the issue of trust can become a problem: “Does she really mean what she’s saying, or is she just being nice?”

Sociologist Lillian Rubin cites one woman as saying that, because women are so expressive and afraid of hurting someone’s feelings, compliments are never assumed to be true. “‘How can I believe she means I look good when she says it automatically, every time I see her?’”

The solution for both sexes is, you guessed it, more and deeper communication. Doing the things necessary to make the other person feel safe — and then vulnerably discussing tough subjects gently and respectfully.

(To learn more about how to handle the most difficult of conversations, click here.)

So you have the tools to build emotional intimacy. But once you have it, how do you keep a solid friendship alive?

6) Upkeep

Friendships require upkeep, like a plant. Yes, some friends are succulents that require little watering but you’re probably forgetting all the ones that turned brown and ended up in the trash.

You need to stay in regular contact. Research shows for solid friendships, every 2 weeks is the minimum. In general, women are much better at this than men.

Women maintain friendships largely through communication and staying in frequent contact… In contrast, only 10% of the men maintained friendships through frequent contact…

But ladies face problems as well. Due to the amount of communication and openness, women are more likely to damage their friendships than men. Survey results show women were more likely to say they lost a friend because of something they said or did (65% vs 50% for men.)

That said, women are more likely to make efforts to repair damaged friendships, while men are more likely to let the relationship dissolve.

So women might want to put more effort in to not getting offended. And given how difficult it can be for men to make “must” friends, they should learn from the ladies and make more attempts to fix a troubled friendship rather than just moving on.

(To learn how neuroscience can teach you to be more emotionally intelligent, click here.)

Alright, we’ve learned a lot. Time to round it all up and see how all this leads to a more meaningful life…

Sum up

This is how to make emotionally intelligent friendships:

Know thyself: To get the friendships you want, you have to know what you want.

Make time: More accurately, make it a priority. We all waste time. So, uh, just don’t waste time alone.

Must, Trust, Rust, Just: The first two are key. Strengthen the “must” and try to elevate the “trust.”

Be proactive: In case you need confirmation, waiting for the phone to ring does not, in fact, make the phone ring.

Communication: Create safety, be vulnerable, be emotionally expressive and use active listening. And a sincere compliment never hurt either, beautiful.

Upkeep: You’re not too busy to send a text message every two weeks. If you think you’ll forget, put it in your calendar.

Research shows your friends often know you better than you know yourself. So not only does being closer to friends make your life better, it’s also the path to getting to know yourself better.

So do what it takes to improve your relationships with friends and you’ll also improve the one relationship that’s key to happiness in life…

The one you have with yourself.

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